The term 'THICK PERSON' can be summarized by the crossword solution 'CLOT'. A CLOT is a mass of thickened or congealed liquid, typically blood, that forms in a body cavity or vessel. Clots are formed when proteins and other substances in the liquid interact and form a gel-like substance. Clots can be dangerous if they form in the arteries or veins, as they can block the flow of blood and cause serious health problems.